你的 LogOnModel 有无参数构造函数吗?它需要一个 DefaultModelBinder 来实例化它.此外，当您发布异常时，请发布异常对象的完整堆栈跟踪，否则我们只是在猜测错误实际发生的位置.

Does your LogOnModel have a parameterless constructor? It needs one for the DefaultModelBinder to instantiate it. Additionally, when you post the exception, please post the full stack trace from the exception object, else we're simply guessing where the error actually took place.